The Russian air force fired at targets around the Crimean city of Kerch on Thursday, despite the Ukrainian peninsula being occupied by Moscow since 2014.
The port city is the gateway to an 18-kilometre bridge that links Crimea to Russia. Ukraine has labelled the bridge - built in 2018 - as a legitimate target in its bid to force the Russian occupiers out of their lands.
"There is no danger for the city or the bridge," Oleg Kryuchkov, an adviser to Crimea's Russian leaders, said on Telegram. He did not name what was targeted.
Residents of Kerch reported on social media that two explosions had been heard.
Russia has threatened massive retaliation in the event of an attack on the rail and road bridge. Traffic on the bridge is running normally, authorities told Russia's Tass agency.
